The pulley and string shown in the figure are smooth and of negligible mass. For the system to remain in equilibrium…

Q: The pulley and string shown in the figure are smooth and of negligible mass. For the system to remain in equilibrium, the angle θ should be

(a)0°

(b)30°

(c)45°

(d)60°

Ans: (c)
Sol: Let T = tension in the string

T = mg

For equilibrium of √2 mg

$\large 2T cos\theta = \sqrt{2}mg$

$\large cos\theta = \frac{1}{\sqrt{2}}$